Adjustable furniture leg

ABSTRACT

A leg structure formed by a pair of telescoping leg members, one of which is provided with a plurality of spaced apertures. A retractable detent is associated with the other leg member. Movable wedging means are associated with the retractable detent. Means are further provided to move the detent and simultaneously the wedging means to and from a locking position wherein the detent is received in one of the apertures and the wedging means forces the first member into frictional contact with the second member. In the open position the detent and wedge means are clear of the slot and the first member.

United States Patent Favreau [4 Oct. 31, 1972 [54] ADJUSTABLE FURNITURE LEG 1,988,037 1] 1935 Furrer ..248/407 2 775 497 12/1956 Alvarez ..108/146 [72] Inventor. Marcel Favreau, Cowansvrlle,

Quebec, Canada 3,178,146 4/1965 Goodale ..248/407 X 73 Assignee: vim Industries Limited, Cowan- Primary Examiner-J. Franklin Foss sville, Quebec, Canada Attorney-Alan Swabey [22] Filed: June 28, 1971 [57] ABSTRACT [211 157292 A leg structure formed by a pair of telescoping leg Related Application Data members, one of which is provided with a plurality of spaced apertures. A retractable detent is associated conilnuatlon-m-pal't 0f 15,332, March with the other leg member. Movable wedging means 1970, abandonedare associated with the retractable detent. Means are further provided to move the detent and simultane- [52] U.S. CL... ..248/188.5, 108/ 144 ously the wedging means to and from a locking posi- [51] Int. Cl. ..A47b 13/00 tion wherein the detent is received in one of the aper- [58] Field of Search ..248/l6l, 407, 408, 409, 157, tures and the wedging means forces the first member 248/423, 354 P, 354 R, 124, 125, 188.5; into frictional contact with the second member. 1n the 108/144, 146, 147; 287/5 82 T open position the detent and wedge means are clear of the slot and the first member.

f d [56] Re cream Cue .5 .T, 8 Draw n i u UNITED STATES PATENTS I 242,804 6/1881 Vanstone ..108/ 146 X PAIEmmuc-m m2 v 3.701.506

' SHEU 1 0F 2 INVENTOR Marcel FAVREAU A TTORNEY PATENTEDnmar m2 SHEET 2 [IF 2 wmmmmgam I Ill J FIG. 8

ATTORNFY ADJUSTABLE FURNITURE LEG This is a continuation-in-part-of Application Ser. No. 15,332, filed Mar. 2, 1970, entitled Adjustable Furniture Leg now abandoned.

BACKGROUND OF THE INVENTION 1 Field of Invention The present invention relates to a leg structure for furniture. More particularly, the present invention relates to an adjustable yet rigid leg structure for fumiture. I

2. Description of Prior Art Many different adjustable leg structures have and are being used. Probably the most common structure employs some form of detent, spring or otherwise biased into a receiving aperture in one of a pair of telescoping leg members. A common drawback of these devices is the lack of means, other than the telescopic arrangement between the leg members, to prevent the relative lateral movement of the legs and provide a stable structure. In some arrangements the detent itself tends to bias one leg member against the other and thereby increase the rigidity of the structure, however, this is an accidental function and one that conventional detents do not properly perform. The spring type of detent, even if it does press one leg member against the other applies only a resilient spring pressure which does not provide the proper rigidity. It has been proposed to provide other positive locking mechanisms to hold the legs in position, such as collars and the like, however, these are relatively difficult to adjust.

SUMMARY OF INVENTION It is the main object of the present invention to provide an easily adjustable furniture leg that is rigidly held in adjusted position and a relatively simple mechanism for accomplishing this result.

Broadly, the present invention relates to a leg structure incorporating a first leg member telescopically received in a second leg member, the first leg member having a plurality of spaced apertures and the second leg member having a retractable detent for cooperation with the apertures, positioning means to insert or retract the detent from the aperture, and wedging means moved by the positioning means in moving the detent into an aperture to wedge the second member against the first member BRIEF DESCRIPTION OF THE DRAWINGS Further features, objects and advantages will be evident from the following detailed description of one embodiment of the invention as illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of a table incorporating legs constructed in accordance with the present invention;

FIG. 2 is a side elevation view of a portion of the leg structure illustrating the locking and clamping mechanism of the present invention; I

FIG. 3 is an end view of the locking structure of the present invention;

FIG. 4 is a section along the line 4-4 of FIG. 3;

FIG. 5 is a side view illustrating a visual aid for facilitating leg length adjustment;

FIG. 6 is a sectional side view of the locking mechanism along sectional lines 66 of FIG. 8;

FIG. 7 is a further view of FIG. 6 showing the locking pin in its retracted position; and

FIG. 8 is an end view showing the leg members and the locking mechanism.

DESCRIPTION OF PREFERRED EMBODIMENTS In the illustrated embodiment, a table or the like 10 has been shown which comprises a top 12 supported by a pair of legs 14 and 16, each of which has a substantially horizontal foot member 18 and a locking mechanism generally indicated at 20. Each of the legs 14 and 16 are substantially identical and therefore only one will be described in detail.

Each of the legs 14 and 16 includes a pair of leg members 22 and 24, with the first leg member 22 being adapted to be telescopically received within the second leg member 24. The leg member 22 has a series of spaced slots 26 on the flat surface 25 thereof facing the locking mechanism 20. Each of these slots 26 extends at an acute angle to the direction of relative movement of the members 22 and 24 when they are telescoped one within the other. Generally, this acute angle will be in the range of about to 60 and preferably will be about 45.

The leg member 24, as above indicated, has a locking mechanism 20 connected to its lower end. The locking mechanism 20 comprises a housing 28 directly secured to the leg 24. Mounted within the housing 28 on suitable bearings 30 fixed in the side walls of the housing 28 is a rod 32. The bearings 30 and rod 32 are arranged to extend substantially perpendicular to the slot 26 to permit entry of the detent 38 and reduces relative movement as will be described hereinbelow. A pair of spaced eccentric wedging members or earns 31 and 32 are keyed or otherwise secured for pivotal movement with the rod 32. Also connected directly to the rod 32 between the members 31 and 33 is a bent rod 34 having a handle forming end 36 and a detent forming end 38. v

The handle forming end 36 projects through a slot 40 in the top 42 of the housing 28 and provides an easily manipulated lever for moving the detent 38 and rod 32 together with the wedging members 31 and 33 into and out of locking position.

The wall of the leg 24 beneath the housing 28 is cut away as indicated at 44 (see FIG. 4) to receive the wedging members 31 and 33 and the detent 38 and provide direct access for these members and detent to the wall 25 and slot 26 of the leg 22. The surface 25 is flat so that the wedges 31 and 33 may pivot about the common pivot rod 32 substantially parallel to this surface and bear uniformly against the surface 25 to force the leg member 22 against the member 24. These members 22 and 24 have been shown as hollow rectangular cross sections, however, any suitable cross sections permitting uniform pressure of wedges on opposite sides of slots 26 and forcing the member 22 against the member 24 may be used.

Each leg member 22 is provided with a series of coded marks which may be in the form of different colored dots 46 while each leg member 24 is provided with at least one aperture 48 (in the illustrated arrangement two appertures are shown) through which the dots 46 are visible (see FIG. 5). The dots 46 are spaced equivalent to the distance between the slots 26 so that by matching the colored dot 46 in the equivalent holesv 48 in the legs 14 and 16, accurate positioning of the legs is assured.

The locking mechanism 20 is operated as follows. The locking handle 36 is moved to its downward position (dotted line position of FIG. 2) and the leg member 22 moved to the desired location within the leg member 24 so that the desired leg length is obtained and a colored dot 46 appears in the hole 48. In this lower position of the handle 36, the detent 38 is clear of the slot 26 in the leg member 22 and the wedges 31 and 33 are free of the surface 25 of the leg member, thereby freeing the two members 22 and 24 for'relative movement. After the leg member22 has been positioned as described above, the'handle ,36 is moved to its upper locking position (solid line position of FIGS. 2, 3 and 4) which places the detent 38 in the selected slot 26 and forces the wedges 31 and 33 into contact with the surface 25 of the leg member 22'to force the opposite side of the leg member 22 against the inner surface of the leg member 24 and stabilize the leg. It will be noted that the wedging members 31 and 33 are in opposite sides of the slot 26 and are laterally spaced on opposite sides of the longitudinal center line of the leg members 22 and 24 and when in locking positions serve to firmly hold the leg members 22 and 24 in position, thereby to provide a relatively stable structure.

The detent pin 38 isreceived within the slot 26 and thereby locks the leg members 22 and 24 in fixed vertical position. The slope of the slot 26 permits the pin 38 which pivots on rod 32 whose pivotal axis substantially perpendicular to the slot 26 to move into the slot 26. This pivoting action to move the detent 38 into the slot 26 provides the required leverage for forcing the wedging members 31 and 33 into locking relationship squeezing the legs 22 and 24 together. Also, the slope of the slot 26 being at an angle to the direction of relative movement between the leg members 22 and 24 results in immediate contact of the sides of the slot 26 with the pin 38 when any relative vertical movement between the members 22 and 24 takes place. Furthermore, any tendency to sift the detent 38 due to relative movement between the leg members 22 and 24 tending to collapse the leg tends to increase the force of the wedging members 31 and 33 against the surface 25 and thereby tends to more securely lock the members 22 and 24 in position, to resist collapse and to rigidify the leg.

Referring now to FIGS. 6, 7 and 8, there is shown a locking mechanism 50 rigidly secured to a face of the outer or second leg member 52 which telescopically receives the inner of first leg member 51 therein. A plurality of circular apertures 53 are equally spaced on a surface of the first leg member 51 and positioned in a plane which coincides with a retractable detent 54 forming part of a locking pin 61 associated with the locking mechanism 50. The locking mechanism so as to move the detent portion of the pin 61 in and out of an associated aperture 53. To retract and insert the detent 54 from an associated aperture 53, a screw cap is secured to the upper end of the locking pin 61 to permit ease of unthreading and threading of the locking pin 61 within the retaining body 55.

As can be seen from FIG. 7, when the locking pin is disengaged with the first leg member 51, the threaded section 59 is at its uppermost position with respect to the retaining body 55, the shoulder 58 abutting with the upper wall of the cavity 57 preventing the pin 61 from further upward movement. In this position, the end of the locking pin or detent 54 clears the outer surface of the first leg member 51, permitting the first leg member 51 to be slid within the second leg member 52, thus adjusting the length of the leg members.

As can be seen from FIG. 6, when the locking pin 61 is in its locking position with an associated aperture 53, the shoulder 58 abuts against the surface of the first leg member 51 in the immediate area adjacent the associated aperture 53. By slightly turning the screw cap 60, under pressure, the pressure is transmitted through the locking pin 61 and the shoulder 58 on the surface of the first leg member 51 about the associated aperture, causing the first leg member 51 to displace itself slightly so that the opposite walls of the leg members at 62 are forced into frictional contact with each other to more securely lock the leg members 51 and 52 in position, to resist collapse and to rigidify the leg structure.

Having described the present invention, modifications will be evident to those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. A leg structure comprising a first leg member telescopically received in a second leg member, a plurality of spaced apertures in said first leg member, a retractable detent on said second leg member, movable wedging means associated with said retractable detent, means for moving said detent and simultaneously moving said wedging means to and from a locking position wherein said detent is received in one of said apertures, and said wedging means forcing said first member into frictional contact with said second member, and an open position wherein said detent and wedge means are clear of one of said apertures and said first member.

2. A leg structure as defined in claim 1 wherein said detent is an end of a locking pin threaded in a body secured on the outer surface of said second leg member, said detent protruding through said surface to move in and out of engagement with an associated one of said apertures in said first leg member.

3. A leg structure as claimed in claim 2 wherein said wedging means is a shoulder formed around said locking pin a predetermined distance from the detent.

end thereof, said shoulder abutting against the surface of said first leg member adjacent said aperture through which said detent is received to force said first member into frictional contact with said second member.

4. A leg structure as claimed in claim 3 wherein said body retaining said locking pin is provided with a cavity in the lower portion thereof to receive said shoulder therein when said locking pin is moved away from its locking position, said shoulder having restricted movement within said cavity whereby said locking pin can be whereby said detent moves in and out of one of said apertures and said wedging means applies sufiicient pressure to force said first leg member into frictional contact with said second leg member. 

1. A leg structure comprising a first leg member telescopically received in a second leg member, a plurality of spaced apertures in said first leg member, a retractable detent on said second leg member, movable wedging means associated with said retractable detent, means for moving said detent and simultaneously moving said wedging means to and from a locking position wherein said detent is received in one of said apertures, and said wedging means forcing said first member into frictional contact with said second member, and an open position wherein said detent and wedge means are clear of one of said apertures and said first member.
 2. A leg structure as defined in claim 1 wherein said detent is an end of a locking pin threaded in a body secured on the outer surface of said second leg member, said detent protruding through said surface to move in and out of engagement with an associated one of said apertures in said first leg member.
 3. A leg structure as claimed in claim 2 wherein said wedging means is a shoulder formed around said locking pin a predetermined distance from the detent end thereof, said shoulder abutting against the surface of said first leg member adjacent said aperture through which said detent is received to force said first member into frictional contact with said second member.
 4. A leg structure as claimed in claim 3 wherein said body retaining said locking pin is provided with a cavity in the lower portion thereof to receive said shoulder therein when said locking pin is moved away from its locking position, said shoulder having restricted movement within said cavity whereby said locking pin can be unthreaded only sufficiently to clear said detent of said apertures.
 5. A leg structure as claimed in claim 2 wherein said locking pin is provided with a screw cap at the end thereof opposite said detent end to permit said locking pin to be threaded and unthreaded in said body whereby said detent moves in and out of one of said apertures and said wedging means applies sufficient pressure to force said first leg member into frictional contact with said second leg member. 